Punch



M ya-1 44. j F. B. GRAHAM I 11,348,380

PUNCH Filed Jul 19, 194$ BY I A TTOR Y8.

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Patented May 9, 1944 UNITED STATES PATENT OFFICE 2,348,380 v I it PUNCH Frank Benjaman Graham, Lansing, Mich. Application July 19, 1943, Serial No. 495,330

1 Claim.

Broadly stated, the object of this invention is to provide novel means for assembling a punch with a punch retainer, the construction being such that, after the punch is assembled with the retainer the punch can neither rotate about its axis nor move longitudinally, until manipulated by an operator.

It is within the province of the disclosure to improve generall and to enhance the utility of devices of that type to which the present invention appertains.

With the above and other objects in view, which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein disclosed, may be made within the scope of what is claimed, without departing from the spirit of the invention.

In the drawing:

Fig. 1 shows in side elevation, a device constructed in accordance with the invention;

Fig. 2 is an end elevation;

Fig. 3 is a plan showing the surface of the block which is entered by the punch;

Fig. 4 is a cross section on the line 44 of Fig. 3;

Fig. 5 is a cross section on the line 55 of Fig.3;

Fig. 6 is an elevation showing the punch.

The device forming the subject matter of this application includes a retainer H, preferably but not necessarily of rectangular outline. The retainer H comprises a block-like head I to which a closure plate 2 is applied. The closure plate 2 is held on the block I by diagonally disposed securing elements 3, such as screws. Diagonally disposed dowel pins 4, preferably forming a rectangle with the screws 3, extend through the block I and the plate 2. The projecting dowel .pins 4 and, the screws 3 form means for locating the retainer on a punch holder (not shown).

The block I has a central guideway 5 which, preferably, is of circular cross section. The block I is supplied with an end bore 6 and with a side bore I, disposed approximately at right angles to the longitudinal axis of the guideway 5. The bores 6 and 'I are spaced apart circumferentially of the guideway 5, and in a direction parallel to the longitudinal axis of the guideway, the bore 1 being an outer bore, and the bore 6 being an inner bore.

A keeper 8, in the form of a ball, is mounted to rotate in the bore I and the constituent material of the block I engages the keeper, as shown at 9, to prevent the keeper from leaving the bore 6 when the punch (hereinafter described) is removed, the keeper however, extending a little way into the guideway 5. The keeper 8 is held in place by a screw I0, threaded into the bore I and held against outward movement by a plug I I in the outer end of the bore 1 and preferably made of hard wax. The keeper 8 has no movement longitudinally of the bore I.

In the bore 6 is mounted a ball latch I2 held, as hereinbefore described, and as shown at 9, in connection with the spherical keeper 8, so that it can project a little distance into the guideway 5, but not roll into the guideway when the punch is removed. A screw abutment III is threaded into the bore 6, a compression spring I5 being interposed between the screw abutment and the ball latch [2. The ball latch I2, therefore, has movement longitudinally of the bore 6. v

The punch is marked by the numeral I6 and may have an enlarged end portion II. The enlarged end portion I! of the punch I6 fits closely, but rotatably and slidably in the guideway 5 of the block I. The part II of the punch I6 is supplied with an L-shaped groove I8, including a longitudinal portion I9, and a transverse portion 20, at the inner end of the part I9 of the groove. The enlarged portion II of the punch I6 is terminally beveled as shown at 2|.

In practical operation, the part II of the punch or similar tool It is introduced into the guideway 5 of the block I, the longitudinal portion I9 of the groove I8 receiving the keeper or projection 8. As the punch I6 is advanced, the ball latch I2 is forced outwardly by the beveled surface 2| of the punch, against the action of the spring I 5. The plate 2 forms a closure for one end of the guideway 5, and by the time that the beveled end 2| of the punch engages the plate, as in Fig. 5, the keeper 8 is in a position to enter the transverse part 20 of the groove I8 in the portion II of the punch.

The punch I6 is rotated, and the keeper 8 enters the transverse part 20 of the groove I8. Thus, the punch I6 is held against longitudinal movement. As the punch I6 is rotated, the outwardly-forced ball latch I2 first rolls on the outer surface of the part II of the punch I6, and ultimately enters the longitudinal portion I9 of the groove IB, the punch being held against axial rotation.

By a reverse operation, in which the operator overcomes the thrust of the spring I5, the punch I6 can be detached from the retainer H.

way, and a tool insertable longitudinally into the 10 guideway, the tool having a superficial groove comprising longitudinal and transverse portions, the outer ball being received in the longitudinal portion of the groove, when the tool is inserted as aforesaid, and the inner ball then engaging the tool to one side of the longitudinal portion of the groove, the tool abutting against the retainer, at the inner end of the guideway, to aline the transverse portion of the groove with the outer ball, the tool thereafter being rotatable with respect to the retainer, to cause the outer ball to enter the transverse portion of the groove, and to cause the inner ball to enter the longitudinal portion of the groove and to engage one side thereof.

FRANK BENJAMAN GRAHAM. 

